Xcode 6.1 Swift中的属性字典

Question

After upgrading to Xcode 6.1 Beta 2 from Xcode 6 Beta 7, the following no longer works:

let font = UIFont(name: "Arial", size: 16)
let colour = UIColor.redColor()
let attributes = [NSFontAttributeName: font, NSForegroundColorAttributeName: colour]

I have tried specifically declaring the dictionary as

let attributes: [NSString : AnyObject] = [NSFontAttributeName: font, NSForegroundColorAttributeName: colour]

but I am receiving the error "Cannot convert ... 'Dictionary' to 'NSString!'". Declaring the key as NSString! rather than NSString complains that NSString! is not hashable. Any clues?

Answer 1

Sorted. As usual, the actual error is a red herring. UIFont(name: , size:) now has an init? initialiser, and so is optional. Correct usage is now :

let font = UIFont(name: "Arial", size: 16)! // Unwrapped
let colour = UIColor.redColor()
let attributes: [NSString : AnyObject] = [NSFontAttributeName: font, NSForegroundColorAttributeName: colour]

or, more correctly:

if let font = UIFont(name: "Arial", size: 16) {
    let colour = UIColor.redColor()
    let attributes: [NSString : AnyObject] = [NSFontAttributeName: font, NSForegroundColorAttributeName: colour]
    // ...
}